How to setup Purescript locally

Setup

First, make sure you have Node installed.

Next, we’ll use the node package manager (npm) to install PureScript.

npm install -g purescript

And to go along with PureScript, we’ll need the Pulp build tool and the Bower package manager.

npm install -g pulp bower

Setup a project directory and open it in your terminal. Run the following three commands.

pulp init

pulp build

pulp run

if its working it should print "Hello sailor!" in the console.

Now we need to install some packages he uses for this course:

bower install purescript-arrays

bower install purescript-lists

Now compile it with pulp build:

pulp build

Now you should be able to go src/Main.purs and start coding.

Code Changes

In the course Vincent is using the try.purescript.org online editor. The editor is a bit out of date with the latest version of purescript and it's packages. So we have to make the following changes to get the code examples to run on our machines.

So lets take some code from lesson one, and put it into Main.purs

src/Main.purs

 module Main where

import Prelude (show, ($), (+), (=<<))
import Control.Monad.Eff.Console (log)
import TryPureScript (render, withConsole)

addMe :: Int -> Int -> Int
addMe a b = a + b

main = render =<< withConsole do
    log $ show $ addMe 5 5

This code will work on try.purescript but it won't work on our machine. Let's make some changes.

We need to remove import TryPureScript (render, withConsole). The TryPureScript package is used to render to the try.purescript console specifically.

import Control.Monad.Eff.Console (log) also needs to be removed and replaced with import Effect.Console (log). This change was made as of purescript-console version 4.0.0.

Then we need to change main = render =<< withConsole do to just main = do.

Your lesson one code should now look like this.

src/Main.purs

 module Main where

import Prelude (show, ($), (+), (=<<))
import Effect.Console (log)

addMe :: Int -> Int -> Int
addMe a b = a + b

main = do
    log $ show $ addMe 5 5

Now save the file, and in your terminal type:

pulp run

If 10! is outputted purescript is ready to be used locally!

Changes to Lesson 10

In lesson 10, all instances of id need to be changed to identity. This change was made as of purescript-prelude version 4.0.0.

The online editor is using purescript-prelude version number 3.1.0. However, the latest version is 4.1.0. The only change that is breaking the code in this lesson is that id was renamed to identity.